US Patent 6854144 Therapeutic mattress system

A generally rectilinear block is made of an elastomer. The block has a horizontal top surface, a parallel bottom surface and a vertical peripheral surface. The block has an upper edge, a lower edge and parallel side edges. The block also has a height, and width and a thickness. A plurality of apertures are cut into the block. A plurality of inserts is fabricated of the same material as the block and of a size and shape corresponding to the size and shape of the apertures.